Electrostatic processor

ABSTRACT

A PROCESSOR IS DESCRIBED FOR REPRODUCING IMAGES FROM MICROFILM AND THE LIKE IN WHICH FLEXIBLE SHEET MATERIAL, SUCH AS PAPER, IS FED THROUGH A CUTTER TO A CONVEYOR. THE SHEET MATERIAL POSITION IS SENSED TO ACTIVATE CUTTING, EXPOSING AND DEVELOPING OPERATIONS. THE CONVEYOR ALLOWS SHEET MATERIAL SLIPPAGE DURING CUTTING. DIFFERENT SHEET SIZES MAY BE OBTAINED BY UTILIZING A PLURALITY OF SENSORS WHICH ARE POSITIONED AT PREDETERMINED LOCATIONS AND WHICH MAY BE INDIVIDUALLY SELECTED FOR CONTROL, EITHER MANUALLY OR AUTOMATICALLY. THE CUTTER MAY BE DEACTIVATED TO PERMIT EXPOSING AND DEVELOPING ON A CONTINUOUS STRIP, IN WHICH CASE EXPOSURE MAY BE SYNCHRONIZED WITH SHEET MOVEMENT BY A TIMING WHEEL.

Feb. 2, 1971 I B. H. JOHNSTON 3,560,036

' T ELECTROSTATIC PROCESSOR Filed Nov. 6, 1967 2 Sheets-Sheet 1 FIG. I.

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ATTORNEYS 00038880000009pofiaaggoofioobo United States Patent Office 3,560,086 Patented Feb. 2, 1971 US. Cl. 355-13 13 Claims ABSTRACT OF THE DISCLOSURE A processor is described for reproducing images from microfilm and the like in which flexible sheet material, such as paper, is fed through a cutter to a conveyor. The sheet material position is sensed to activate cutting, exposing and developing operations. The conveyor allows sheet material slippage during cutting. Different sheet sizes may be obtained by utilizing a plurality of sensors which are positioned at predetermined locations and which may be individually selected for control, either manually or automatically. The cutter may be deactivated to permit exposing and developing on a continuous strip, in which case exposure may be synchronized with sheet movement by a timing wheel.

This invention relates to reproducing apparatus and, more particularly, to a processor for producing a reproduction of an image on flexible sheet material.

Processors for producing a reproduction of an image on flexible sheet material, such as paper, are frequently used for making hard copies (i.e., printed copies) of information displayed on microfilm, a cathode ray tube screen, etc. Such a processor may be useful in an information retrieval system wherein information stored on microfilm or in a computer memory, or both, may be printed out as needed on conventional size sheets of paper. One type of processor Which may be utilized for such purposes is sometimes referred to as an electrostatic processor.

An eletrostatic processor generally operates by exposing a sheet of photoconductive electrostatically charged paper to a light image which it is desired to reproduce. Variation in the amount of light to which the surface of the paper is exposed produces a latent image on the paper by producing a corresponding variation in the electrostatic charge thereon. A latent image is then developed by spreading a toner, such as a pigmented resin, over the surface of the paper so that the toner is held to the paper in accordance with the latent image thereon. The toner on the paper may then be fused by applying heat, resulting in a permanently printed image on the paper.

Certain problems arise in the design and construction of processors generally and of electrostatic processors in particular. One such problem arises in connection with the positioning of the paper for exposure to the image and, if desired, for cutting. Instantaneous starts and stops of paper motion may provide a satisfactory regulation of paper position, but result in considerable complexity in design and operation. The common requirement of uniform paper motion in the developing and fusing operations adds complication to the design of rapid intermittent motion mechanisms. Moreover, such mechanisms may incur problems because of paper slippage and because of the inertia of various elements in the system.

It is sometimes desirable that a processor be adaptable to reproducing images on sheets of various sizes, or on a long continuous strip of paper or other material. The use of precut sheets of different sizes is one solution, however, different size sheets add complexity to storage and to changing over the processor to accommodate the particular size desired. For example, changeover of the processor for different size sheet may require somewhat complex and time-consuming alterations to 'be made by an operator.

In a processor which utilizes a continuous sheet of flexible material, such as paper, taken oflf a supply roll, it may be necessary to thread a leader strip of the material through the processor before beginning operation. This may be an inconvenience and incur a substantial expenditure of operator time. Moreover, material required for a leader is wasted and increases materials cost for the operation.

In electrostatic processors, particularly, certain problems may be encountered. Among such problems is that wear to developer parts and to toner particles is incurred because of the abrading action of the toner particles against parts of the developer and against themselves. This is especially true where, as is sometimes the case, the toner is entrained in iron particles or filings. It is therefore desirable that such wear be minimized. With respect to the paper in an electrostatic processor, the electrostatic charge placed thereon may dissipate with time. In a processor which is operable on intermittent demand, non-uniformity in electrostatic charge resulting from varying storage times, or varying times in delay of the passage of paper through the processor, may result in development of nonuniform images.

It is an object of the present invention to provide an improved processor for producing a reproduction of an image on flexible sheet material.

Another object of the invention is to provide a processor of the type described utilizing a continuous roll supply of flexible sheet material and wherein threading of a leader for the material through the processor before beginning operation is not required.

It is another object of the invention to provide a processor of the type described wherein instantaneous starts and stops are not required and wherein slippage of sheet material and inertia of various elements present minimal difficulty.

A further object of the invention is to provide an electrostatic processor capable of producing uniform quality prints upon intermittent demand.

It is a further object of the invention to provide an electrostatic processor in which wear to developer components and to toner particles is minimized.

Still another object of the invention is to provide a processor adapted for operation automatically in accordance with a programmed set of instructions.

Other objects of the invention will become apparent to those skilled in the art from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a schematic side view of a processor constr-ucted in accordance With the invention;

FIG. 2 is a schematic diagram illustrating the electrical circuitry of the processor of the invention; and

FIG. 3 is a top view of a portion of microfilm from which the processor of the invention can reproduce an image.

Very generally, the processor of the invention operates to produce a reproduction of an image on flexible sheet material. The processor includes means for exposing sheet material to the image and means for developing the reproduction of the image on the exposed sheet material. A continuously operating conveyor transports the sheet material to the exposing and developing means, the sheet material being supplied in continuous form to the conveyor from a supply station. At least one sensor is positioned adjacent the conveyor and senses the position of the material, producing a control signal. A cutter, positioned between the supply station and the conveyor, re-

sponds to the control signal to cut the sheet material a predetermined distance from the leading edge thereof.

Referring now more particularly to FIG. 1, a schematic view of a processor constructed in accordance with the invention may be seen. Paper for the processor is supplied from a paper roll 11 mounted on a spindle 12. The paper, indicated at 13, is drawn from the roll 11 by a feed roller 14, driven by a motor described below and illustrated in FIG. 2. The paper is held against the surface of the feed roller 14 by a pinch roller 16. The pinch roller is mounted on a shaft 17 which is positioned in a slot 18 in the frame 15 of the processor. A suitable spring, not illustrated, may be utilized to bias the pinch roller against the paper feed roller, and the handle 19 is utilized to rotate hook 20 under shaft 17, thereby lifting roller 16 from the paper feed roller 14 to permit the leading edge of the paper to be passed into the space between the two rollers when processor operation is being set up.

Cutting of the paper 13 into sheets of a desired size is accomplished by the paper cutter indicated generally at 21. The paper cutter includes a fixed blade 22 and a movable blade 23. The movable blade is attached to a cylinder 24 mounted on a spindle 26 in fixed position with respect to the path of the paper 13. A handle 27 extends from the cylinder 24 so that the cutter may be operated manually. This enables the leading edge of the paper to be squared when a new roll is being started through the processor.

The illustrated processor is of the electrostatic type, using a paper 13 which may be charged with an electrostatic charge, the charge dissipating in accordance with the impingement of light thereon. Such paper may be chemically treated or coated to enhance its electrostatic charge properties. Preferably, the upper side as the paper unrolls is coated with a suitable chemical which is particularly adapted to retaining a negative charge which readily dissipates when struck with light. The charger 28 is of the corona charge type and includes two charge grids 29 and 31 maintained at a suitable potential by electrical means not illustrated. As the paper moves between the charging grids 29 and 31, both surfaces of the paper are charged to a uniform potential, negative on the upper side and positive on the lower side.

After passing through the charger 28, the paper is moved to a station at which it is exposed to the image to be reproduced, and then to a station wherein the image is developed, by means of a conveyor 32. The conveyor includes one or more endless perforated belts 33 which are driven by a drive roller 34. The drive roller 34 is mounted on a spindle 36, and is driven by a motor subsequently described and illustrated in FIG. 2. Two idler rollers 37 and 38 are also provided engaging the belts 33. A pair of idlers 39 and 41 are provided for reasons which will be subsequently explained.

In order to hold the paper on the conveyor as it passes through the exposing station, a vacuum platen or enclosure 42 is disposed underneath the belts 33 between the rollers 38 and 34. The belts are perforated and the vacuum platen 42 maintains a partial vacuum on the underside of the belts to thereby hold the paper against the upper surface of the belts. A blower, not illustrated, maintains the partial vacuum in the vacuum platen.

As the paper passes along with the belts 33 and over the vacuum platen 42, it is exposed to the image which is to be reproduced. The precise point at which exposure occurs is controlled in a manner subsequently described and is in alignment with an image lens 43. The image lens is mounted in a lens housing 44 having variable aperture therein as will be subsequently described. Microfilm, indicated at 46, is movable, frame by frame, past the lens 43 between the lens and a gas-filled flash lamp 47. A suitable condensing lense 48 is positioned between the lamp 47 and the film 46. In accordance with the magnification provided by the image lens 43 and in accordance with the size of the aperture opening within the housing 44, as will be explained below, an image to be reproduced from a microfilm frame aligned with the lens 43 is projected onto the surface of the paper 13. The image may be of a size the limits of which are indicated by the dotted lines 49 and 51, or may be of a size as indicated by the dotted lines 52 and 51, depending upon the position of the aperture shutter, as described below.

As previously mentioned, the belts 33 are continuously driven. This makes it much easier to achieve a uniform speed than would be the case if intermittent operation were to be utilized. Because belt speed is uniform, and because, as will be explained, paper position is sensed directly While the paper is being carried on the belts, uniformity in both cutting and exposing operations is readily achieved. The individual sheets are not out until the leading edge of the paper is a predetermined distance past the cutter, and consequently paper size, is not dependent upon the speed or amount of rotation of the intermittently operable feed rollers. A uniform belt speed also results in uniform speed of the paper through the developer and the fuser, for a uniform image quality.

After being exposed to the image, the paper 13 is passed on the belts 33- over the main drive roller 34. Two small pressure rollers 53 hold the edges of the paper against the belts at the underside of the roller 34 to insure that the paper will pass into a developer, generally indicated at 54. Development of the electrostatic image, latent in the charge pattern on the exposed paper, is accomplished by the developer, and operation of the developer is started by a developer sensor 55. The developer sensor is located just prior to the developer and its function is described in greater detail below. The developer brushes the exposed surface of the paper with a toner, consisting of small black particles of thermoplastic material. The toner is mixed with iron particles and the thermoplastic material is attracted to the iron particles by a triboelectric effect. The actual spreading of the toner on the surface of the paper is accomplished by a rotary brush 56 which is magnetized so that the iron particles in which the toner is entrained cling to the brush. The brush is rotated by a motor, described below and contained in a housing 57. Also enclosed in the housing 57 is a trough, not illustrated, from which the rotary brush 56 picks up the iron particles and toner mixture. The toner is supplied to the trough in the housing 57 from a replaceable cannister 58 by means of a toner dispenser 59. The cannister 58 sits in a rotary holder 61 and discharges toner into the dispenser 59. The dispenser 59 is provided with a suitable rotary screw conveyor or similar device for moving the toner into the trough in the housing 57. The motor for driving the rotary holder 61 and the rotary device 62 will be described below. As the toner is brushed onto the surface of the paper 13 by the rotary brush 56, the stronger fields of the charge pattern or latent image on the surface of the paper pull the toner from the iron particles, developing the image thereon. The charge pattern or latent image on the paper is provided with a background charge by means of a background grid charge element 63. This element stabilizes the development process by providing a slightly repelling charge on the previously uncharged or white areas of the paper to prevent over-development or graying. The charge provided by the background grid charge element 63 may be regulated to achieve a desirable balance between black and white extremes in the developed image.

While the paper is passing through the developer 54, the belts 33 are moved out of the way and around the developer by passing over the idler 39 and under the idler 41. As the paper emerges from the developer 54, however, it re-engages the surface of the belts and a further vacuum platen or chamber 64 is provided at this point. A partial vacuum is maintained by the blower, not illustrated, as was the case with the vacuum platen 42. Thus, the paper clings to the surface of the belts 33 and is drawn from the developer by the belts.

As the belts pass over the roller 37, the paper 13 falls or peels from the belts and passes through a fuser generally indicated at 66. The fuser has a pair of guides 67 which insure that the leading edge of the paper is pushed between a pair of heating elements 68 and 69. The temperature of the heating elements is regulated so that the toner particles clinging to the paper will fuse to each other and to the paper. The result is a permanent or hard copy that may be handled without smudging and consequent loss of information. The lower element 69 generally heats the toner, while the upper element 68 assists by heating the paper to insure fusing of the toner thereto. The heat produced by the elements may be controlled by a suitable thermostatic control to constantly maintain the heat within specified tolerances.

After passing through the fuser 66, a roller 71 and a set of short belts 142 grip the paper between them and draw it from the fuser to pass it into a takeup tray 72. The rollers 71 and belts 142 may be driven in synchronism with the main drive roller 34. As will be explained subsequently in greater detail, the processor may be operated for reproducing images on an uncut continuous sheet, in which case the cutter 21 is not used. In such an instance, a takeup roller 73 is provided mounted on a spindle 74 for rolling up the continuous strip or sheet of material as it passes between the roller 71 and belts 142.

In the illustrated apparatus, the cutter 21 may be operated to produce two sizes of paper sheets. For example, where the width of the paper coming off the paper roll 11 is 11 inches, sheet sizes of 8 /2 x 11 and 11 x 14 may be produced. As mentioned before, the processor may also be operated in a strip mode. Operating of the cutter for producing the different sizes of the paper is initiated by either the small size sensor 76, or the large size sensor 77. Both sensors are mounted adjacent the conveyor 32 and subsequent to the cutter 21. The sensors 76 and 77 sense the arrival of the leading edge of the paper and, as will be described subsequently, command the cutter 21 to sever the paper. The precise position of the sensors 76 and 77 is selected so that, taking into account any delays in the operation of the cutter 2'1, the paper will be cut at exactly the desired size. Because of the uniform speed of the belts 33, uniformity of paper size is assured. During the cutting operation, when the cutter blades 22 and 23 meet, the paper will momentarily be stopped. Such is permitted, however, because the paper 13 may slide on'the perforated belts until the cut is completed and then proceed along with the belt. This avoids the need for such complex positioning expedients as instantaneous start and stop mechanisms.

Between the pressure roller 53 and the developer 54,

a developer sensor '55 is provided. Specific operation of this device is described below, however, the developer sensor initiates operation of the developer, the latter being off when not in actual use. By minimizing the operating time of the developer through utilizing it only when needed, wear to the developer parts and to the individual particles of toner, due to abrasion, is minimized Referring now to FIG. 2, the general control circuitry of the processor of the invention is illustrated schematically. Prior to initiation of a copy cycle, a conveyor motor 84 is turned on by a switch 86 and a blower motor 87 is turned on by a switch 88. The conveyor motor 84 drives the main drive roller 34, and the blower motor 87 operates the blower, not illustrated, for maintaining a partial vacuum in the platens 42 and 64.

The initiation of a copy cycle and the particular mode of operation of the processor may be selected in any convenient way. In the illustrated processor, however, cycle irfitiation and mode selection is accomplished by means of the presence or absence of coded dots at positions 89, 91, 92 and 93 (see FIG. 3) on the microfilm 46. The positions are aligned in a row along one edge of the film between the images 94 and 96 and the perforations 97. The presence or absence of a dot at the first position 89 for each frame is sensed by the copy sensor 78, suitably located in the image projection system, such that the copy sensor 78 produces a starting pulse. Such a pulse is applied to the paper feed logic circuit 79. The copy sensor may be a photoelectric device or a magnetic device, depending upon the dot characteristics used. The absence of such a dot will cause the processor to bypass a particular image on the microfilm unless operation of the processor is initiated manually. Manual initiation of processor operation may be accomplished by a suitable switch or other convenient means for providing a starting pulse to the paper feed logic circuit.

The command or starting pulse is recevied by the paper feed logic circuit 79, which is designed in accordance with known logic circuit techniques to produce an output pulse in response to receipt of such a command. This output pulse is fed to a feed motor control circuit 81 which functions as a switch to close and permit power from a source 82 to be applied to the motor 83. As previously mentioned, the motor 83 drives the feed roller 14 to withdraw paper from the paper roll 11. When the feed motor control circuit 81 operates to start the feed roller motor 83, a signal is fed back to the paper feed logic circuit 79 in order to hold the feed motor control circuit in a condition such that power is continuously supplied to the feed roller motor 83.

The second dot position controls the size of the aperture in the housing 44, previously mentioned, in a manner described more fully below.

The third dot position 92 on the microfilm 46 determines the size of the paper sheet which is to be cut by the cutter. The presence of a dot indicates that a small size sheet (e.g., 8 /2 x 11) is to be produced, whereas the absence of a dot indicates that a large size sheet (e.g., 11 x 14) is to be produced.

The fourth dot position 93 on the film controls the strip or continuous mode of operation of the processor. The presence of a dot indicates that the processor is to operate in the continuous mode whereas the absence of a dot indicates that the processor is not to operate in such a mode.

The presence and absence of dots at the positions 92 and 93 are sensed, respectively, by the sheet size sensor 98, and the strip mode sensor 99. The sensors 98 and 99, which are preferably the same type of device as the copy sensor 78, are positioned suitably in the image projection apparatus. Pulses produced by the sensors 98 and 99 are passed to a mode logic circuit 101. The mode logic circuit controls the operation of the processor in a manner which is simulated by the multiple switch 102. The multiple switch 102 has three positions, the small size mode position, the large size mode position, and the strip mode position. Such positions are indicated adjacent the mode logic circuit 101 in FIG. 2. As illustrated, the switch 102 is in position for o eration of the processor in the small size mode. Accordingly, operation of the processor in such mode 'will be described first.

In the small size mode of operation, and with the switch 102 in the position illustrated, the small size sensor 76 will apply a pulse to the paper feed logic circuit 79. The paper feed logic circuit 79, in response to a pulse from the small size sensor 76, applies a control signal to the feed motor control circuit 81 to remove power from the feed roller motor 83, thus stopping the paper feed.

The same pulse from the small size sensor 76 is applied to a cutter logic circuit 103. A command from the cutter logic circuit 103 is then applied to the cutter motor control circuit 104 which acts as a switch to apply driving power from the source 106 to the cutter motor 107. The cutter motor is drivingly coupled to the roller 24 illustrated in FIG. 1. The cutter motor 107 is a reversible motor, and the direction of operation thereof may be con trolled by microswitches conveniently located to sense the position of the cutter blades 22 and 23. Mechanical arrangements to satisfactorily accomplish such sensing are known in the art and, accordingly, details thereof will not be described herein. The functions of the microswitches are such, however, as to cause the cutter blades to sever the paper as desired and to return to an open position. At the open position, the switches are arranged to cause the cutter motor control circuit 104 to cut off power from source 106 to the cutter motor 107. Although the operation of the cutter 21 is not instantaneous, the small size sensor 76 may be placed at a position such that delay and paper feed rate will be taken into account and the paper will be severed at precisely the right length.

Image size in the small size mode is controlled by a shutter 108 which is constructed to partially obstruct the aperture in the lens housing 44 (FIG. 1). The shutter insures that the image size will conform to the corresponding sheet size (as may be viewed by comparing the dotted lines 49, 51 and 52 in FIG. 1), and particularly that the image size will be smaller in the small size mode. Operation of the shutter is accomplished by a solenoid 109 connected through a resistor 111 to a suitable DC source 112. A damping diode 113 is connected across the coil to the solenoid 109.

As the small size sheet passes along with the belts 33 (FIG. 1) into alignment with the projector lens, its true aligned position is sensed and the flash lamp 47 is actuated to flash an image on the paper. Actuation of the flash lamp 47 is accomplished by a pulse produced by the small size sensor 76 as the trailing edge of the sheet arrives at the sensor. The axis of the lens 43 is positioned with respect to the small size sensor so that the image will be appropriately centered. When the trailing edge of the out small size sheet arrives at the small size sensor 76, the pulse produced thereby is passed to a flash circuit 114 which operates to produce a high voltage flashing pulse for the lamp 47. The flash circuit may be of any suitable type, such as a capacitor discharge-high voltage coil type of circuit. 7

After exposure, the exposed sheet is passed to the developer 54 for development. The developer sensor 55 initiates operation of the developer by applying a pulse to the developer logic circuit 116 when the leading edge of the paper arrives at the developer sensor. The developer logic circuit applies a command to the developer motors control circuit 117 to initiate operation of a brush motor 118 and a dispenser motor 119. The brush motor 118 operates the rotary brush 56, and the dispenser motor 119 operates the toner dispenser in the housing 59, both of which are illustrated in FIG. 1. In order that the developer operate with exactly the right amount of toner, the dispenser motor 119 is connected through a variable resistance 121 to the control circuit 117 and the AC source 122 so that its speed may be regulated independently of the speed of the brush motor.

When the trailing edge of the sheet passes the developer sensor 55, a pulse is applied to the developer logic circuit 116, which eventually produces a command to the control circuit 117 to turn 011 the motors 118 and 119. In order to insure that the sheet has passed completely through the developer before the developer stops operation, the developer logic circuit is provided with a delay capacitor 123. The capacitor is of a value such that the control circuit 117 will be delayed in turning off the motors for a sufiicient length of time.

In the absence of a dot at the position number 92, the mode logic circuit 101 operates as though the switch 102 were in the middle or large size mode position thereof. Initiation of the copy cycle including the starting of the feed roller motor is accomplished in the same manner as described in connection with the small size mode of operation. Initiation of cutter operation, however, and the stopping of the feed roller motor 83, will not occur until the leading edge of the paper is sensed by the large size sensor 77. Thus, a longer feed time occurs and a correspondingly larger piece of paper is cut.

Initiation of the flash is accomplished by the small size sensor 76 precisely in the manner as was described in connection with the small size cycle. In the case of the large size mode of operation, however, the paper can accommodate either the larger or smaller image sizes. Accordingly, the operation of the solenoid 109 and the shutter 108 is controlled through a shutter logic circuit 124 by means of an image size sensor 126. The sensor 126 is located suitably in the projector for sensing the presence or absence of a dot at the position 91. The presence of a dot causes the shutter logic circuit to energize the solenoid 109 and move the shutter into the smaller image size position. The absence of a dot at position 91 causes the shutter, which is suitably biased to its wider position, to remain at such position. Although the smaller image can be accommodated by the smaller sheet ize, it may be desirable to use the larger sheet size with a smaller image in order to provide substantial margins on the sheet. The image size sensor and shutter logic circuit, as described, provide for this.

In the presence of a dot at the position 93 on the microfilm, the strip mode sensor causes the mode logic circuit 101 to, in effect, move the switch 102 to the lower or strip mode position. In the strip mode position, the lower pole on the switch 102 deactivates the cutter logic circuit to prevent operation of the cutter 21. In addition, the solenoid 109 is energized to move the shutter 108 into position for the small image size which is used exclusively in the strip or continuous mode operation.

Initiation of the strip mode operation causes the paper feed logic circuit 79 to provide a continuous control signal to the feed motor control circuit 81 and hence continuously operate the feed roller motor 83. During strip mode operation, a timing wheel 127 is engaged with the surface of the paper 13 as it passes over the drive roller 34. The timing wheel, which is mounted on an arm 128 and may be positioned manually by a lever 129, has a marker or indicator 130 thereon and is of a diameter to rotate once during the interval between the time each flash should be initiated for strip mode operation. A suitable sensor 131 mounted adjacent the wheel 127 senses the rotation thereof by sensing the passage of the marker or indicator and applies timing pulses to the flash circuit 114. The flash circuit thus fires the flash lamp 47 at the desired times to produce a series of images along the strip of paper being fed through the processor.

The strip mode operation may be utilized for producing long charts and will terminate in the absence of a dot at the position 93 on the microfilm. The absence of such a dot will cause the mode logic circuit 101 to change the processor back to another mode of operation, de pending upon the presence or absence of other dots at other positions.

It will be noted that it is unnecessary that paper motion start or stop instantaneously. If initial slippage of the paper occurs in the feed rollers, or if the rollers accelerate slowly due to inertia of the supply roll, the size of the paper which is cut is unaffected. Moreover, the paper from the supply roll need not stop immediately, when the motor 83 is de-energized since no harm is done if the paper continues through the cutter 21 after a cut is made and before the drive rollers finally stop. It is unnecessary to thread a leader strip through the apparatus, since all that need be done is to engage the leading edge of the strip between the pinch roller 16 and the feed roller 14 and to square off the leading edge of the paper by hand operation of the cutter 21. Moreover, it may be noted that uniform speed in the feed rollers is unnecessary and not critical to the operation.

Because the conveyor 32 which moves the paper through the exposing and developing stations is of the continuous type, it may be kept in continuous motion for a reduction of the complexity, noise and wear associated with rapid intermittent motion mechanisms. Moreover, the paper motion is easily kept smooth and uniform, resulting in more uniform processing.

Charging of the paper does not occur until immediate- 1y prior to exposure, insuring that a uniformly high quality image will result. Moreover, changeover between various sizes of sheets and modes of Operation is readily facilitated in the apparatus, yet only one type of paper supply need be maintained. The changeover between sheet sizes requires no manual intervention, and changeover to strip or continuous mode operation requires only a minimal manual operation. Thus, the processor may be controlled by a computer program which generates the microfilm with suitably placed code dots. Of course, the processor may be used with other image producing means besides microfilm, such as a cathode ray tube. Also, the processor operation may be controlled by program through the use of other information storing means hesides microfilm.

It may therefore be seen that the invention provides an improved processor for producing a reproduction of an image on flexible sheet material. The processor does not require instantaneous starts and stops, and slippage and inertia problems are minimized. No threading of the sheet material through the processor prior to operation is necessary. The processor provides uniform quality prints upon intermittent demand by electrostatic charging, exposure and development, and is readily controlled by computer program and the like. Wear to the developer and to particles of the toner is minimized through provision of intermittent developer operation.

Various modifications of the invention in addition to those shown and described herein will be apparent to those skilled in the art from the foregoing description and accompanying drawings. All such modifications are intended to fall within the scope of the appended claims.

What is claimed is:

1. A processor for producing a reprOduction of an image on flexible sheet material, including in combination, means for exposing the sheet material to the image, means for developing a reproduction of the image directly on the exposed sheet material, continuously operating conveyor means for transporting the sheet material to said exposing and developing means, supply means for feeding the sheet material in continuous form to said conveyor means, means adjacent said conveyor means for sensing the leading edge of the sheet material and producing a control signal, cutting means located after said feeding means but before said continuously operating conveyor means and responsive to a control signal produced by said sensing means to cut the sheet material a predetermined distance from the leading edge thereof.

2. A processor according to claim 1 wherein said conveyor means comprise at least one perforated belt a d means for producing a partial vacuum on the side of said belt opposite the sheet material for permitting said sheet material to temporarily stop in response to resistance on the sheet material during cutting.

3. A processor according to claim 1 including means positioned between said cutting means and said exposing means for charging the sheet material to a predetermined electrostatic potential.

4. A processor according to claim 1 including means for selectively deactivating said cutting means and means for operating said exposing means periodically to produce a succession of images on the sheet material.

5. A processor according to claim 4 wherein said operating means include a wheel for contacting the sheet material to be rotated thereby, means for producing a signal for each revolution of said wheel, and means for utilizing such signals to synchronize said exposing means with the movement of the sheet material.

6. A processor according to claim 1 including further sensing means positioned adjacent said conveyor means and prior to said developing means for sensing the leading and trailing edges of the sheet material and producing control signals, said developing means including at least one rotary element therein and a means for driving same, said element driving means being responsive to the control signals produced by said further sensing means to operate only when sheet material is Passing through said developing means.

7. A processor according to claim 6 wherein said further sensing means include means for delaying the termination of operation of said element driving means until the sheet material has passed through said developing means.

8. A processor according to claim 6 wherein said rotary elements of said developing means include means for applying toner to the surface of the sheet material, and means for supplying toner to said applying means, and wherein said developing means further include means for regulating the speed of said supplying means independently of said applying means.

9. A processor according to claim 1 wherein said sensing means comprise a plurality of detectors positioned along the path of movement of the sheet material at different predetermined distances from said cutting means, said sensing means further comprising means for producing a control signal in response to the arrival of the leading edge of the sheet material at a preselected one of said detectors, and means for applying the control signal to said cutting means, said cutting means being operable in response to receipt of the control signal to cut the sheet material at a size dependent on the selected one of said detectors.

10. A processor according to claim 1, wherein said exposing means include a variable size aperture for varying the size of the exposed area on the sheet material.

I11. A processor according to claim 1 wherein said sensing means include means for sensing the osition of the cut sheet material and for operating said exposing means when the cut sheet material is at a predetermined position.

12. A processor according to claim 9 wherein said sensing means include means for producing a control sig nal for operating said exposing means in response to the arrival of the trailing edge of the sheet material at one of said detectors.

13. A processor for producing a reproduction of an image on flexible sheet material, including in combination, means for exposing the sheet material to the image, means for developing a reproduction of the image directly on the exposed sheet material, continuously operating conveyor means for transporting the sheet material to said exposing and developing means, supply means for feeding the sheet material in continuous form to said conveyor means, means adjacent said conveyor means for sensing the position of the sheet material and producing a control signal, and means between said feeding means and said conveyor means and being responsive to a control signal produced by said sensing means to cut the sheet material a predetermined distance from the leading edge thereof said conveyor means having at least one perforated belt and means for producing a partial vacuum on the side of said belt opposite the sheet material for permitting said sheet material to temporarily stop in response to resistance on the sheet material during cutting.

References Cited UNITED STATES PATENTS 3,075,493 1/1963 Cerasani 35513X 3,091,169 5/1963 Tanini 355109 3,181,420 5/1965 Rautbord 35514 3,357,326 12/1967 Hunstiger 3554 2,415,424 2/1947 Gaebel 355-64X JOHN M. HORAN, Primary Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,560,086 Dated February 2, 1971 Inventor(s) Bevan on It is certified that error appears in the above-identified paten and that said Letters Patent are hereby corrected as shown below:

Column 1, lines 4 and 5 instead of "Rochester, N. Y.

read "San Diego, California".

Signed and sealed this 31st day of August 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,J'R. WILLIAM .E. SCHUYLER, JR. Attesting Officer Commissioner of Patents USCOMM-DC FORM PO-105O (10-69) 

